In modern cataract procedures, also called extracapsular cataract extraction, a hole is cut in the anterior capsular bag. This may be done using laser devices. Subsequently, the natural lens is removed. In the remaining parts of the capsular bag, in many suggested procedures an IOL is placed. The IOL more or less maintains its position in the empty bag.
Usually, an IOL is provided with haptics. These haptics extend radially from a lens of an IOL. After implanting an IOL, these haptics usually engage the inside circumference of the remaining capsular bag part in order to more or less keep the optics, for instance a lens, of the IOL centred and positioned in the capsular bag.
For improving fixation of the position of an IOL, many designs were proposed. U.S. Pat. No. 6,027,531 describes in its abstract “An intraocular lens for use in extracapsular cataract extraction has a haptic pa[r]t that surrounds the optical pa[r]t of the lens and further contains a groove of such shape to accommodate the anterior and posterior capsules of the lens bag after anterior capsulorhexis, extracapsular cataract extraction and posterior capsulorhexis. The lens is preferably inserted in a calibrated, circular and continuous combined anterior and posterior capsulorhexis, slightly smaller than the inner circumference of the groove as to induce a stretching of the rims of the capsular openings. This new approach is believed to prevent the appearance of secondary opacification of the capsules, allows a very stable fixation of the intraocular lens and ensures a tight separation between the anterior and posterior segment of the eye. This new principle of insertion is called the bag-in-the-lens technique, in contrast with the classical lens in-the-bag technique.”. Placement of this IOL requires skills and the capsular bag may get damaged. If after insertion the capsular bag ruptures, the IOL will not maintain its position.
In U.S. Pat. No. 6,881,225, in the abstract an intraocular lens structure for reducing complications is described. The intraocular lens structure comprises an optic, a support and a closing fixture. The closing fixture is a groove or a valley formed on the side portion of the optic of the intraocular lens. The valley is formed by the optic and a protrusion projecting posteriorly from the optic. The groove or the valley in the optic is made engaged with the posterior capsular opening generally over the entire circumference of the groove or the valley to close the opening of the posterior capsule. Like most of the current IOL structures, the structure also uses its haptics for keeping the structure in the capsular bag. The groove holds the posterior part of the capsular bag.
U.S. Pat. No. 5,171,320 in its abstract describes an intraocular lens system adapted to be implanted within a generally circular opening in an anterior wall of the capsular bag which normally contains the crystalline lens of an eye. The intraocular lens system includes a lens body having an annular groove which is formed in a peripheral portion thereof in a plane substantially perpendicular to an optical axis of the lens body. The lens body includes an optically effective portion located radially inside the annular groove, and an anterior lens portion and a posterior lens portion located on respective anterior and posterior sides of the annular groove. The intraocular lens system is secured in position within the circular opening such that an annular flap portion of the capsular bag which surrounds the circular opening is accommodated within the annular grove in the lens body.
Known IOL's and IOL systems usually do not completely correct optical errors in the eye. Usually, emmetropy, in which light is exactly focused on the retina, is not attained. A residual error remains. Often, the patient still needs spectacles, or receives laser treatment in order to correct the usual +0.5 to +1.5 Dioptre refractive error that remains. In the art, an additional lens was suggested that clips on an implanted IOL. Examples of these are the following documents.
U.S. Pat. No. 4,932,971 in its abstract describes a clip-on optic assembly for clipping in situ onto a previously implanted intraocular lens to change its optical characteristics without removal from the eye, comprising a lens body having a plurality of spaced apart resilient clip members extending therefrom and outwardly terminating in clips for gripping the implanted lens peripheral edge to clip the assembly thereon. At least one clip is formed as a bent end sufficiently resilient for temporary unbending and displacement over and across the implanted lens peripheral edge to grip the clip thereon, e.g. with the clips being of selected length for maintaining the lens body optical axis concentric or eccentric to the implanted lens optical axis, the assembly upon insertion into the eye being clipped onto the implanted lens such that a bent end clip is last manipulated onto such peripheral edge.
U.S. Pat. No. 5,366,502 in its abstract describes a supplemental intraocular lens that is provided for either preoperative or postoperative attachment to a conventional implanted intraocular lens to provide an adjustable or removable multi-focal optic or to provide a necessary optic of spherical, cylindrical or combination shape for refractive error correction in aphakic patients. An intraocular lens system is also provided including a primary intraocular lens modified to provide for securing a supplemental corrective intraocular lens to the primary lens. Either the primary or supplemental lens could be formed of a suitable multi-focal lens, or both lenses could be mono-focal. The primary intraocular lens is implanted in the anterior chamber of an eye, or in the posterior chamber of an eye between the capsular bag and the iris.
WO2008094518 in its abstract describes a multi-component intraocular lens implanted in an optical system of a human eye, including one or more foldable removable components, each component being foldable. One component acts as a base lens, including a flange with an aperture or a slot. Another component acts as a mid lens and a third component acts as a top lens, which engages the mid lens. The top lens and mid lens may be joined to or integrated to form an optical assembly. The top lens, the mid lens or the optical assembly may include at least one projection that engages the slot of the base lens. A medical adhesive may be applied to an outer circumferential surface of the top lens to join the top lens to the mid lens or may be applied to a top surface of the top lens opposing a bottom surface of the mid lens. Because the lens components are foldable, they may be inserted into the eye using an incision smaller than the diameter of the unfolded lens. The removable components may be used to correct various medical conditions of the eye, as well as to improve and enhance vision, and for cosmetic purposes.
EP2422746 discloses according to its abstract an intraocular implant for placement in the eye, e.g. as part of a cataract operation or crystalline lens extraction refractive operation, has at a peripheral portion of the implant a groove which engages with the lip of a single capsulotomy only formed in the lens capsule of the eye. The implant will normally be a lens, but may instead be a bung or plug for occluding an opening made in the capsule. The groove may be a continuous groove around the periphery of the implant, or there may be a series of individual spaced-apart grooves formed as projections protruding from the periphery. Instead of a single groove, a pair of axially spaced-apart grooves may be provided, which engage with respective capsulotomies formed in an anterior and a posterior part of the capsule. The posterior groove is preferably of a smaller mean diameter than the anterior groove. The description shows an embodiment with “a series of projections projecting from the circumference of the lens portion”, referring to very specific embodiments in the drawings.
WO2013112589 according to its abstract discloses a modular IOL system including intraocular primary and secondary components, which, when combined, form an intraocular optical correction device, wherein the secondary component is placed on the primary component within the perimeter of the capsulorhexis, thus avoiding the need to touch or otherwise manipulate the capsular bag. The secondary component may be manipulated, removed, and/or exchanged for a different secondary component for correction or modification of the optical result, on an intra-operative or post-operative basis, without the need to remove the primary component and without the need to manipulate the capsular bag. The primary component may have haptics extending therefrom for centration in the capsular bag, and the secondary component may exclude haptics, relying instead on attachment to the primary lens for stability. Such attachment may reside radially inside the perimeter of the capsulorhexis and radially outside the field of view to avoid interference with light transmission.